This week France became the first country in the world to enact a ban on short-haul domestic flights.
According to the new law, airlines may not operate flights between two French cities when there's a rail connection available that takes less than 2 hours and 30 minutes.
The measure is an attempt to reduce carbon emissions caused by air travel, which the World Wildlife Fund describes as "currently the most carbon intensive activity an individual can make,” reports CNBC.
In a statement, France's transport minister, Clément Beaune, praises the new ban on short-haul flights as a "world first" that's "an essential step and a strong symbol in the policy of reducing greenhouse gas emissions."
Critics would place an emphasis on the "symbol" part, and likely dispute that the measure is "strong."
Other French destinations are either too far apart or don't meet the railway requirement, despite France's extensive train system.
What's more, the ban doesn't seem to apply to private jets, and connecting flights are exempt as well.
Originally, climate activists and some politicians had proposed barring flights for trips connected by train rides of 4 hours or less, but the time window was reduced following objections from airlines and certain regions at risk of losing flights.
The BBC reports that the French consumer group UFC-Que Choisir argued at the time for keeping the 4-hour limit because, as the group put it, "On average, the plane emits 77 times more CO2 per passenger than the train on these routes, even though the train is cheaper and the time lost is limited to 40 minutes."
Despite the limited scope of the short-haul ban at present, it could eventually expand to other city pairs in France if faster rail service arrives. Some environmentalists are hoping the movement to require travel by rail rather than short flights spreads beyond France to other parts of Europe.
As the Evening Standard points out, that will depend in part on the completion of projects like the new 36-mile Mont Cenis Base Tunnel in the Alps. That feat of engineering promises to cut in half the more than 7 hours currently required to travel by train between Paris and Milan.
Of course, you don't have to wait for the government to outlaw domestic flights to start traveling by train in France. As Frommer's France explains, the state-owned railway, SNCF, is "fabled for its on-time performance and comfy trains" that get you "from Paris to just about anywhere else in the country within hours."